Here is my experience of PP stamping with no approval letter and no infopass appointment.
Went to Houston INS office @6:30am, talked to the security officer at the gate and told him that my wife will be travelling tomorrow so need her PP stamped today.
7:00am I was inside the building and talked to another officer who was issing the ticket numbers. He asked the approval letter and I showed him the e-mail confirmation he was not familier with the e-mail confirmation he looked several times and then looked into the airline ticket and the itenerary and asked my wife to show some ID and he matched her name. And then he asked what is the emergency I said it was family emergency that she has to go tomorrow. And then the officer issed a ticket number and said since I do not hav Infopass appt I have to wait for a while.
11:45am Went the the counter gave her the e-mail confirmation she asked about ID my wife gave her EAD card and then after looking to her system she said the their system is not updated and unless that is update whe cannot stamp the PP, she said I can see her approval on one screen but on the other screen it is not showing anything about the class of green card, the system will be updated after they dispatch the letter. She then said the my wife can use the AP while comming back there is no problem with that. And she also said that if I get the approval letter then she can able to stamp her PP without any problem. So did not had any luck at this time........... have to reschedule her trip now.....
I already booked two appt using Infopass on 2nd week of november. Hopefully by that time I will get the approal letter by mail.
Rajibda